Inherent in the criteria for many of the disorders in DSM-IV (American Psychiatric Association, 1994) are cognitive impairments, such as attentional and language dysfunctions. The proposed research will examine five hypotheses about potential common and differential deficits in schizophrenia and depression related to working memory and sustained attention. Cognitive differences between schizophrenics and depressives will be assessed by examining ERP component latency and amplitude, as well as accuracy and recall performance. ERP data will be obtained as responses to target and nontarget tones in Experiment 1 and to sentences in which the terminal words are either semantically congruent or incongruent with the text preceding it in Experiment 2. Both experiments rely on well researched phenomena and measures in the normative cognitive psychophysiology literature and on specific procedures developed in the applicant's laboratory. Both experiments have been successfully piloted with inpatient volunteers.